Ideal Security Inc. SK927B SK927 Fold-Away Window Casement Handles for 5/16" Splines, Fits Most Operators, 2 Pack, Bronze DISCREAT APPEARANCE: Folding crank neatly hugs the window sill DISCREAT APPEARANCE: Folding crank neatly hugs the window sill SNAP-ON: No screws, easy snap on installation. Only works with splines that have a snap-in notch VERIFY COMPATIBILITY WITH YOUR CURRENT HARDWARE: Replaces standard 10-tooth handles for splines with 12 teeth and a diameter of 11/32 Folding crank handles for casement window operators